Method for producing a borohydride

ABSTRACT

A method for producing a borohydride is described and which includes the steps of providing a source of borate; providing a material which chemically reduces the source of the borate to produce a borohydride; and reacting the source of borate and the material by supplying heat at a temperature which substantially effects the production of the borohydride.

GOVERNMENT RIGHTS

The United States Government has rights in the following inventionpursuant to Contract No. DE-AC07-99ID13727 between the U.S. Departmentof Energy and Bechtel BWXT Idaho, LLC.

TECHNICAL FIELD

The present invention relates to a method for producing a borohydride,and more specifically to a single step reactive metal combustion processwhich reduces oxygen from a source of borate, and which simultaneouslyhydrogenates the borate to synthesize the resulting borohydride.

BACKGROUND OF THE INVENTION

The prior art is replete with numerous teachings which relate to thedevelopment of environmentally friendly fuels, that is, fuels which canbe used in place of traditional hydrocarbon based energy sources, andwhich are currently utilized in most overland vehicles. Much researchhas been directed, as of late, to the use of fuel cells in combinationwith conventional technology, in so-called “hybrid vehicles.”Notwithstanding the advances that have been made in hybrid vehicledesign, no single, fuel storage system has been developed which canstore the fuel which is typically consumed by a fuel cell, that ishydrogen. For transportation applications, a compact light-weight,responsive and affordable hydrogen storage medium is required foroverland vehicle applications. In automotive applications, it isestimated that to provide a 300 mile driving range for a typicaloverland vehicle, would require 5-10 kilograms of usable hydrogen,depending upon the size of the vehicle. Beyond the issues of providing asuitable hydrogen storage medium, other engineering issues would alsoneed to be addressed such as the operating pressure and temperature thatthe hydrogen may be provided at, the life cycle of the hydrogen storagemedium, and any requirements for hydrogen purity which may be imposed bythe fuel cell which is utilized with the overland vehicle.

Other issues, that are currently trying to be addressed for overlandvehicle applications, include the methodology for replenishing thehydrogen storage medium; the types of refueling conditions to replenishthe storage medium, that is rate, and time that is necessary to performthis process; and the hydrogen release rate that might be achieved fromsuch a process. Other important issues directed to safety, toxicity andsystem efficiency would also need careful consideration. Those familiarwith the current state of the art agree that no material currentlyavailable today appears to meet all the needs for the storage of largeamounts of hydrogen, which might be utilized by a hybrid vehicle. Whilehydrogen can be stored on an overland vehicle in a substantially pureform, such as compressed gas, or in a cryogenic liquid, these presentobvious difficulties with respect to replenishing the hydrogen sourceonce it has been depleted. While some developments have occurred withrespect to storage systems for gaseous and liquid forms of hydrogen, itis fair to say that such systems are unduly complex and still may notmeet the requirements as outlined by recent information released by theU.S. Department of Energy.

In view of these difficulties, many skilled in the art have initiatedresearch directed to chemical compounds which can store hydrogen andthen later release it for use in an overland vehicle. In this regard,the storage of hydrogen and chemical compounds offers a much wider rangeof possibilities to meet transportation requirements. However, no singlematerial which has been investigated to date exhibits all the necessaryproperties.

Finding an effective hydrogen storage medium material therefore, is oneof the most difficult challenges facing designers of hybrid or electricoverland vehicles. As of late, a number of investigators have consideredthe feasibility of synthesizing light-metal hydrides, such asborohydrides, for use in overland vehicle applications. However, as oflate, the current process for synthesizing borohydrides, for example, isa lengthy solvent process as more fully understood by a study of U.S.Pat. No. 6,670,444 the teachings of which are incorporated by referenceherein. The attractiveness of utilizing a borohydride is understood by astudy of the formula set forth below.NaBH₄+2H₂O→4H₂+NaBO₂+heat (300KJ).

As seen from the formula, noted above, the spent material is sodiummetaborate. The regeneration of the borohydride from the spent borates,as noted above is a lengthy solvent process which is complex andeconomically unattractive.

Therefore, a method of producing a borohydride which avoids thedetriments associated with the prior art practices is the subject matterof the current patent.

SUMMARY OF THE INVENTION

A first aspect of the present invention relates to a method forproducing a borohydride which includes the steps of providing a sourceof borate; providing a material which chemically reduces the source ofthe borate to produce a borohydride; and reacting the source of borateand the material by supplying heat at a temperature which substantiallyeffects the production of the borohydride.

Another aspect of the present invention relates to method for producinga borohydride which includes the steps of providing a source of borate;providing a source of hydrogen; providing a source of a reactive metaland/or carbonaceous material; mixing the sources of borate, hydrogen andthe reactive metal and/or carbonaceous material; and reacting themixture of the sources of borate, hydrogen, and the reactive metaland/or carbonaceous material by heating the mixture to a temperaturewhich is effective to reduce the oxygen from the borate andsubstantially simultaneously hydrogenate the source of borate, which hasbeen previously reduced, to produce a borohydride.

Still further, another aspect of the present invention relates to amethod for producing a borohydride which includes the steps of providinga source of a hydrated borate; providing a source of a reactive metal;mixing the source of hydrated borate with the source of the reactivemetal to form a mixture; providing a chemical reactor and supplying themixture to the chemical reactor; sealing the chemical reactor followingthe step of supplying the mixture to the chemical reactor; evacuatingthe chemical reactor to create a negative pressure within the chemicalreactor; and heating the mixture in the chemical reactor to atemperature which facilitates the conversion of the hydrated borate to aborohydride and the production of hydrogen gas.

Moreover, still another aspect of the present invention relates to amethod for producing a borohydride which includes providing a source ofanhydrous borate; providing a source of a reactive metal; mixing thesource of the anhydrous borate with the source of the reactive metal toform a mixture; providing a chemical reactor; continuously supplying themixture to the chemical reactor; supplying a source of hydrogen gas tothe chemical reactor while the mixture is received therein; and heatingthe mixture and the hydrogen gas which are in the chemical reactor to atemperature which facilitates the conversion of the anhydrous borate toa borohydride.

These and other aspects of the present invention will be described ingreater detail hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described below withreference to the following accompanying drawings.

FIG. 1 is a graph of the thermodynamic predictions for the reactions ofaluminum and magnesium to synthesize a borohydride according to themethod of the present invention.

FIG. 2 is a graphical depiction of the Gibbs Free Energy of Reaction forthe materials titanium, and zirconium which are used to reduce a sourceof borate to produce a borohydride. The reactions which are graphicallydepicted are shown on that drawing.

FIG. 3 is a graphical depiction of the Gibbs Free Energy of Formation(ΔG_(f)) for different oxides which are produced by means of themethodology of the present invention.

FIG. 4 is a graphical depiction of the comparative Gibbs Free Energy forthe Reactions (ΔG_(R)) as identified in that drawing.

FIG. 5 is a greatly simplified schematic view of one arrangement whichmay be utilized to practice the method of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

This disclosure of the invention is submitted in furtherance of theconstitutional purposes of the U.S. Patent Laws “to promote the progressof science and useful arts” (Article 1, Section 8).

The methodology for the present invention is best understood by a studyFIGS. 1-5, respectively. As understood by these drawings, themethodology of the present invention relates to a method for producing aborohydride which includes a first step of providing a source of borate;providing a material which chemically reduces the source of the borateto produce a borohydride; and reacting the source of borate and thematerial by supplying heat at a temperature which substantially effectsthe production of the borohydride. The present methodology uses a solidstate reactive metal combustion process to reduce the oxygen from theborate and which is followed substantially simultaneously byhydrogenation to synthesize the resulting borohydride. This chemicalreaction occurs in a single step which, in one form of the invention,occurs at substantially atmospheric pressure, and the source of hydrogenfor the hydrogenation comes from a source of hydrogen gas; anotherhydrocarbon, or simply water.

Referring now to FIG. 5, this drawing depicts a greatly simplifiedschematic view of an arrangement to practice the methodology of thepresent invention. The arrangement for generally practicing themethodology of the present invention is generally indicated by thenumeral 10. The present methodology reacts a source of borate 11 such assodium metaborate with other materials which include a source ofhydrogen gas 12; a source of water 13; a source of a hydrocarbon 14; asource of carbon 15; and first, second and third reactive metals 16, 17and 18, respectively. In the discussion which follows, the chemicalformulations, as described below, have all been made by reference to astarting material which includes sodium metaborate as might be suppliedat 11. This material has been selected primarily because it is widelyavailable. However, it will be recognized that other similar hydridescould be utilized in the present process with equal success. Withrespect to the various materials as referenced above, it should beunderstood that the source of hydrocarbon 14 may include a substancesuch as methane, but other similar materials (both gaseous and liquid)will work with equal success. Still further, various carbonaceousmaterials may be provided for the source of carbon 15, all of which canbe provided in a form whereby it may be combusted or reacted as will bedescribed hereinafter. The sources of reactive metals 16, 17 and 18 arechosen from the group of reactive metals which include aluminum,magnesium, titanium, chromium, silicon, tantalum, vanadium, andzirconium, and their various alloys.

Examples of reactions which may be conducted in accordance with thepresent methodology are set forth below and are divided into groups 1, 2and 3, respectively. The Group 1, reactions are noted immediately,below.

Group 1 NaBO₂ + 2H₂O + 4Mg → NaBH₄ + 4MgO NaBO₂ + 4H₂O + 4Al → NaBH₄ +2Al₂O₃ + 2H₂ (4) NaBO₂ + 2H₂O + Mg + 2Al → NaBH₄ + MgAl₂O₄ NaBO₂ +2H₂O + 2Ti → NaBH₄ + 2TiO₂ NaBO₂ + 2H₂O + 2Zr → NaBH₄ + 2ZrO₂ NaBO₂ +4H₂O + 4Cr → NaBH₄ + 2Cr₂O₃ + 2H₂ NaBO₂ + 3H₂O + 2V → NaBH₄ + V₂O₅ + H₂NaBO₂ + 3H₂O + 2Ta → NaBH₄ + Ta₂O₅ + H₂ NaBO₂ + 2H₂O + 2Si → NaBH₄ +2SiO₂ NaBO₂ + Mg + CH₄ → NaBH₄ + MgO + CO NaBO₂ + 2Al + CH₄ + 2H₂O →NaBH₄ + Al₂O₃ + CO + 2H₂ NaBO₂ + 2Al + C + 2H₂O → NaBH₄ + Al₂O₃ + CONaBO₂ + 2Al + H₂ + H₂O → NaBH₄ + Al₂O₃ (3)

It will be understood that the reactions of Group 1 include amongothers, reacting a source of borate 11, along with a source of water 13,or other source of hydrogen 14, and a reactive metal as indicated, toproduce a borohydride and a substantially stable oxide as a by-product.

In the Group 2 reactions, as noted below, the reactions include a sourceof borate 11 and which further is combined with a source of hydrogen gas12 and a corresponding reactive metal 16, 17 and/or 18, respectively toprovide a resulting source of borohydride and a substantially stableoxide.

Group 2 NaBO₂ + 2Mg + 2H₂ → NaBH₄ + 2MgO 3NaBO₂ + 4Al + 6H₂ → 3NaBH₄ +2Al₂O₃ (1) 2NaBO₂ + Mg + 2Al + 4H₂ → 2NaBH₄ + MgAl₂O₄ NaBO₂ + Ti + 2H₂ →NaBH₄ + TiO₂ NaBO₂ + Zr + 2H₂ → NaBH₄ + ZrO₂ 3NaBO₂ + 4Cr + 6H₂ →3NaBH₄ + 2Cr₂O₃ 5NaBO₂ + 4V + 10H₂ → 5NaBH₄ + 2V₂O₅ 5NaBO₂ + 4Ta + 10H₂→ 5NaBH₄ + 2Ta₂O₅ NaBO₂ + Si + 2H₂ → NaBH₄ + SiO₂ 2NaBO₂ + 2Al + CH₄ +2H₂ → 2NaBH₄ + 2Al₂O₃ + CO (2)

In the Group 3 reactions, identified below, these reactions include asource of borate 11 which is combined with a source of hydrogen whichmay include hydrogen gas 12 or water 13, plus one or more reactivemetals 16, 17 or 18 or other material to produce a resulting borohydrideand a substantially stable oxide as shown. For purposes of thisapplication, silicon is a reactive metal.

Group 3 NaBO₂ + 2H₂O + Mg + 2Al → NaBH₄ + MgAl₂O₄ 2NaBO₂ + Mg + 2Al +4H₂ → 2NaBH₄ + MgAl₂O₄ NaBO₂ + H₂O + H₂ + Mg + Si → NaBH₄ + MgSiO₃NaBO₂ + 2H₂O + 2Mg + Si → NaBH₄ + Mg₂SiO₄ NaBO₂ + H₂O + H₂ + Mg + Ti →NaBH₄ + MgTiO₃ NaBO₂ + 3H₂O + Mg + 2Ti → NaBH₄ + MgTi₂O₅ + H₂ 2NaBO₂ +H₂O + H₂ + 2Al + Si → 2NaBH₄ + Al₂SiO₅ 2NaBO₂ + H₂O + 3H₂ + Mg + 2Ti →NaBH₄ + MgTi₂O₅

Referring now to FIG. 1, the thermodynamic predictions for selectivegroup 1, 2 or 3 reactions, noted above, to synthesize a resulting sodiumborohydride from a source of borate, which includes sodium metaborate 11are shown. Each of the reactions as seen in FIG. 1 shows a differentcondition for the Gibbs Free Energy Reaction (ΔG_(R)). In this regard,and for the reactions 1 and 2 of Group 2, it will be seen that each hasa negative free energy of reaction which occurs below 1500 K. Yetfurther, for reaction 3 (Group 1), this chemical reaction has a negativeGibbs free energy of reaction below 2000° K. Further, reaction 4 (Group1) has a negative Gibbs free energy of reaction below 3000° K. Thisinformation suggests that thermodynamic conditions are favorable for aborohydride to form below these temperatures. By reviewing theinformation shown on FIG. 1, it will be noted that several of thereactions have negative Gibbs free energies at all temperatures.

All the reactions as graphically depicted in FIG. 1 show a negativeGibbs free energy of reaction at 1000° K. Still further, several of thereactions also are thermodynamically favorable at high temperatures,that is, greater than 2000° K. These specific reactions are candidatesfor thermal plasma processing. Therefore, based upon this information,the inventor has concluded that chemical reactions can be conducted attemperatures both above and below 1000° K. in order to generateborohydride from a suitable source of borate 11.

The present methodology for synthesizing a borohydride from a source ofborate such as sodium borate is not limited to the use of reactivemetals such as aluminum and magnesium only. Metals such as titanium,chromium, silicon, tantalum, vanadium and zirconium or mixtures thereof,and which may be provided from the reactive metal sources 16, 17 and 18may also be provided and which are reacted with the source of borate 11in order to produce the resulting borohydride.

FIG. 2 depicts the Gibbs Free Energy of Reaction (ΔG_(R)) plots fortitanium, and zirconium, and the corresponding reduction of a source ofborate 11 to form a borohydride. It will be noted from a review of thisdrawing that the titanium and zirconium reactions are closely similar toeach other. It is evident, from reviewing the data in this graph thatall the identified reactions are thermodynamically favorable attemperatures of less than about 1150° K. Further, above this sametemperature, reaction 2, as identified in that same drawing, becomesthermodynamically unfavorable as compared to reaction 5. Still further,reactions 1 and 4, as identified in FIG. 2, are favorable both atrelatively high and low temperatures. As seen, the Gibbs Free Energy ofReaction for reaction 1 turns substantially positive at about 2825° K.and at 3700° K. for reaction 4. Yet further, reactions 3 and 6 arethermodynamically favorable at all temperatures. It will be noted thatthese two reactions, as set forth in FIG. 2 also utilize a source ofcarbon 15 for reduction, and the production of carbon monoxide as abyproduct, appears to stabilize the respective reactions atsubstantially all temperatures. Reactions 1, 3, 4 and 6, as seen in FIG.2, appear to be candidates for thermal plasma processing as will bediscussed in greater detail, hereinafter, to produce a resultingborohydride.

Referring now to FIG. 3, a graphical depiction is provided of the GibbsFree Energy of Formation (ΔG_(F)) of Different Oxides as contemplated bythe methodology of the present invention. As seen in FIG. 3, the GibbsFree Energy of Formation for crystal, liquid (C,L) and gas phases (G) ofsodium metaborate are shown. As a general matter, it will be seen thatbelow 3500° K., aluminum, titanium, and zirconium are more effectivethen magnesium for reactive metal reduction of the source of borate 11to synthesize a resulting borohydride. However, at temperatures slightlygreater than 3000° K. carbon reduction of the borates is more favorableto synthesize the resulting borohydride. The data as provided in thedrawings suggest that it is feasible to use thermal plasmas tosynthesize borohydrides using either reactive metals 16, 17 or 18 orcarbonaceous materials 14 or 15 or a combination of both to reduceborates at temperatures of greater than about 1500° K.

Referring now to FIG. 4, it will be seen that in addition to thereaction of a single reactive metal to synthesize a resultingborohydride, a mixture of reactive metals offers additional pathways tosynthesize borohydrides from a source of borate 11. As illustrated inFIG. 4, aluminum, magnesium and borate form stable oxides of magnesiumaluminate which is a natural mineral. In this regard, magnesiumaluminate is a very stable oxide and considered much more so thanalumina. It is speculated that the formation of a stable oxide permitsaluminum and magnesium to extract the oxygen from the source of borate11. FIG. 4 also shows the comparative Gibbs Free Energy of Reaction(ΔG_(R)) plots for these and other reactions. As seen in the reactionsas identified in FIG. 4, water is the source of hydrogen to form theresulting borohydride. However, a source of hydrogen gas 12 can be useddirectly in these reactions to synthesize a resulting borohydride. Theextreme temperature end for these several reactions is between about2500° to about 3000° K. As a result, these reactions are suitable for athermal plasma process to produce a resulting borohydride. On the otherhand, the lower temperature end of these reactions, that is, less thanabout 1200° K. are suitable for other low temperature reaction processesas will be described hereinafter.

Referring now to FIG. 5, the respective sources of borate 11, hydrogen12, water 13, hydrocarbon 14, carbon 15, and first, second and thirdreactive metals 16, 17 and 18 are individually and selectively mixedtogether in various combinations to provide a mixture which istransmitted along a course of travel and supplied to a pair of chemicalreactors which are generally indicated by the numerals 21 and 22,respectively. These respective chemical reactors, which are generallygraphically depicted, may be continuous flow chemical reactors, orfurther batch reactors which can be substantially sealed during thesubsequent chemical reaction process. As seen in FIG. 5, the firstchemical reactor 21 is defined by a housing 23. Still further, thehousing defines a cavity 24. As seen in FIG. 5, a heat radiator 25 whichmay be manufactured from a ceramic or similar material is positioned inthe cavity 24 and is operable to radiate heat energy from a heated fluid(gas or liquid) which is received therein. Still further and as seen atFIG. 5, an electrically energized supplemental heating coil 26 ispositioned thereabout and is disposed in heat transferring relationrelative to the cavity 24 in order to provide supplemental heat tofacilitate the reaction of the mixture of materials which are beingselectively supplied from the various sources 11-18, respectively. Asseen by reference to FIG. 5, the various sources of material 11-18 areindividually and selectively mixed to provide a resulting reactivemixture which is then supplied by way of a conduit, or other suitableconveying means 27 to the cavity 24. The reactive mixture thereafterchemically reacts to provide a resulting borohydride. Any byproducts arethereafter removed by way of a conduit, or other conveying means whichis generally indicated by the numeral 28. These products are receivedinto a storage container 29.

Referring still to FIG. 5, it will be seen that in the methodology ofthe present invention, an electrical generation facility is provided andwhich is generally indicated by the numeral 40. The electricalgeneration facility could include a facility which is powered by fossilfuels of various types; or as seen in FIG. 5, the facility could utilizea nuclear reactor which is generally indicated by the numeral 41. Itshould be understood that both nuclear powered, as well as fossil fuelgenerated electrical generation facilities could be used in combination.It is understood that during the process of generating electricity,either fossil fuel is burned to generate heat, or in a nuclear reactor41 a plurality of fuel rods 42 are utilized to generate heat energy.This heat energy is subsequently used to produce high pressure steamwhich is then employed with a steam turbine to generate electricity. Asseen in FIG. 5, however and with respect to the use of a nuclear reactor41, it should be understood that the nuclear reactor is gas cooled(typically by helium) and the heat energy produced by the nuclearreaction, is removed from the nuclear reactor by the heated helium gasand by the pathway 43. This heated cooling gas is bifurcated into twoportions or pathways, as indicated. A first portion of this heatedcooling gas travels to, and is received in, the heat radiator 25.Further, another or second portion of the heated cooling gas is divertedto a heat exchanger which will be discussed below. The heated coolinggas, once received in the heat radiator 25 releases its heat to same.This same heat is then released by the heat radiator 25 to heat thereactive mixture which has been previously received in the firstchemical reactor 21 to a temperature of less then about 1000° C. Thistemperature facilitates the chemical reactions earlier discussed. Thecooling fluid received from the nuclear reactor 41 then exits theradiator 25 by means of the pathway 44 and passes through a first heatexchanger 45 whereby any remaining residual heat energy is transferredby way of the heat exchanger 45 to a first source of water 46 which isutilized to produce steam.

As seen in FIG. 5, a second heat exchanger 50 is provided and which isfurther coupled in fluid flowing relation relative to the electricalgeneration facility and more specifically to the nuclear reactor 41. Asillustrated, the second heat exchanger 50 receives the second portion ofthe heated cooling gas from the nuclear reactor, and is operable totransmit the heat energy received from the second portion of the heatedcooling gas to a second source of water 51 which is mixed with the firstsource of water and then supplied to the second heat exchanger 50.Therefore, it will be seen that the first source of water 46 and thesecond source of water 51 are heated by the high temperature cooling gasprovided from the nuclear reactor 41 to provide a source of steam 52.This source of steam is then coupled in fluid flowing relation relativeto a conventional steam turbine 53. Under the influence of the highpressure steam, the steam turbine is operable through mechanical energy54 to operate a generator 55 which generates a source of electricity. Asseen, the electrical power output from the generator 55 is supplied bymeans of a pair of electric conduits 60 to selectively energize theheating coil 26 which is disposed in heat transferring relation relativeto the first chemical reactor 21. Still further, the electrical poweroutput from the generator 55 is also supplied to the second chemicalreactor 22 as seen by the arrow labeled 61. The electrical power outputof the generator 55 is operable to create a thermal plasma throughconventional means and which acts upon the previously described reactivemixture which is prepared from the plurality of materials 11-18,respectively in order to generate a resulting borohydride. As earlierindicated, the first and second chemical reactors 21 and 22 may comprisecontinuous flow, as well as batch reactors. Upon being exposed to thehigh temperature plasma, as generated by the electrical power output ofthe generator 55, the high temperature plasma reactions proceed toproduce a resulting borohydride which is then removed by means of theconduit or other conveyance 62 from the reactor 22 and is received inthe storage container 29. As earlier noted, the thermal plasma inducedcarbon reduction reactions are typically high temperature reactions,that is, they occur at greater than about 1500° C. Therefore, it will beseen that the electricity generated from the gas cooled nuclear reactor41 provides electrical power to facilitate two borohydride productionprocesses substantially simultaneously, that is, a low temperatureprocess which occurs at less than about 1000° C. and a second hightemperature process which is implemented by means of a high temperatureplasma which has a temperature of greater than about 1000° C.

Referring now to FIGS. 1-5, the methodology of the present inventionbroadly includes, as a first step, providing a source of borate 11; andproviding materials 12-18 which reduces the source of the borate toproduce a borohydride; and reacting the source of borate 11 and thematerials 12-18 by supplying heat at a temperature which substantiallyeffects the production of the borohydride. In the methodology as shown,the production of the resulting borohydride occurs in a single step.Still further, the method as described above, includes a step ofproviding a source of hydrogen 12, and wherein the source of hydrogenhydrogenates the source of the borate 11 to produce the borohydride.This source of hydrogen may be selected from the group which compriseshydrogen 12, water 13, and/or a hydrocarbon which is generally indicatedby the numeral 14. In addition to the foregoing, the material selectedto reduce the source of borate 11 may comprise a reactive metal 16, 17or 18 or a carbonaceous material 14 or 15.

As contemplated by the present invention, the step of providing amaterial which chemically reduces the source of borate to produce aborohydride includes a step of providing a reactive metal 16, 17 or 18and further conducting a solid state combustion reaction of the reactivemetal. Still further, the present invention also contemplates a step ofproviding a reactive metal 16, 17 or 18 and further conducting a solidstate chemical reaction substantially without the combustion of thereactive metal(s) 16, 17 or 18. As noted earlier, the presentmethodology can also be accomplished by reacting a mixture of reactivemetals 16, 17 and/or 18. The methodology may also include a step of asolid state combustion of some of the reactive metals 16, 17 and/or 18and a solid state reaction substantially without combustion of theremaining reactive metals. In the methodology as shown, the group ofreactive metals as earlier discussed chemically reduces the source ofborate 11 when reacted with the source of borate at a temperature ofgreater than about 330° C. In the arrangement as shown, the reactivemetal and/or mixture of reactive metals which are selected reacts withthe source of borate 11 at a temperature which produces the borohydrideand a substantially stable oxide as a byproduct. As seen in FIG. 5 andas discussed previously, the temperature at which the borohydride isproduced in the first reactor 21 is less than about 1000° C. Stillfurther, the temperature at which the borohydride is produced in thesecond reactor 22 is greater than about 1000° C.

As illustrated in FIG. 5, the method of producing borohydride of thepresent invention includes a step of reacting the source of borate andthe material 12-18 by supplying heat at a temperature. In this regard,the step of supplying heat at a temperature includes the steps ofgenerating heat at a temperature from the operation of an electricalgeneration facility 40, and generating electricity 61 from the operationof the electrical generation facility. As earlier noted, the electricalgeneration facility 40 may be powered by a combustible fossil or otherfuel or further powered by a nuclear reaction which occurs in a gascooled nuclear reactor 41. As earlier discussed, before the step ofgenerating heat at a temperature from an electrical generation facility40, the method further includes the steps of providing a first reactor21, and supplying the source of borate 11, and the selected material(s)12-18 to the first reactor 21; providing a cooling fluid 43 for removingheat energy which is generated by the operation of the electricalgeneration facility 40, and wherein the cooling fluid is heated to atemperature; and supplying the previously heated cooling fluid to thefirst reactor 21 to effect the reaction of the source of borate 11 andthe individual material(s) 12-18. In addition, the methodology of thepresent invention further includes the steps of providing a secondreactor 22, and supplying the source of borate 11 and selectedmaterial(s) 12-18, respectively to the second reactor 22; and supplyingthe source of electricity 61 which is generated by the electricalgeneration facility 40 to the second reactor 22 to generate a thermalplasma which heats the borate and the selected material(s) to atemperature which effects the production of the borohydride. Stillfurther, and as discussed earlier, the method of the present inventionfurther includes the step of supplying the electricity 60 which isgenerated by the operation of the electrical generation facility 40 toheat the first reactor 21 to effect the reaction of the source of borateand the material to produce the borohydride.

In the methodology of the present invention, the method also includesthe steps of providing a source of borate 11; providing a source ofhydrogen 12; providing a source of a reactive metal and/or carbonaceousmaterial 14-18, respectively; mixing the sources of borate, hydrogen andthe reactive metal and/or carbonaceous material; and reacting themixture of the sources of borate, hydrogen, and the reactive metaland/or carbonaceous material by heating the mixture to a temperaturewhich is effective to reduce the oxygen from the borate 11 andsubstantially simultaneously hydrogenate the source of borate 11, whichhas been previously reduced, to produce a borohydride which is thenreceived in a storage container 29. As discussed above, the step ofreacting the mixture of the borate, hydrogen and the reactive metaland/or carbonaceous material by heating the mixture to the temperatureresults in the combustion of the reactive metal and/or carbonaceousmaterial. In the practice of the present methodology, the method mayfurther include a step of providing a mixture of reactive metals 16, 17and 18 and/or carbonaceous materials 15. In the step of reacting themixture of the borate, hydrogen, and reactive metal and/or carbonaceousmaterial by heating, it should be understood that the methodology can bepracticed by the use of a high temperature plasma, or without the use ofa high temperature plasma, or the heating achieved, at least in part, bythe use of a high temperature plasma. In this regard, the method furtherincludes steps of providing a first reactor 21, and a second reactor 22,and supplying, at least in part, the mixture which includes the sourceof borate 11, hydrogen 12, the reactive metal 16, 17 and 18 and/orcarbonaceous materials 14 and 15 to each of the first and secondreactors, and heating the mixture to the temperature which is effectiveto reduce the oxygen from the borate and the substantial simultaneoushydrogenation of the source of borate 11 to produce the borohydride. Inthe methodology as seen most clearly by reference to FIG. 5, the methodincludes the steps of coupling the first reactor 21 in heat receivingrelation relative to an electrical generation facility 40, and whereinthe electrical generation facility, during operation, generates heat asa byproduct, and further generates a source of electricity 61; andcoupling the source of electricity to the second reactor 22 tofacilitate the formation of a high temperature plasma. Still further,the method may include a step of coupling the source of electricity 60to the first reactor 21 to increase the temperature of the same reactor.

OPERATION

The operation of the described embodiment of the present invention isbelieved to be readily apparent and is briefly summarized at this point.

As described herein, a method of converting a first material into asecond material includes the steps of providing a first chemical reactor21; providing a second chemical reactor 22; coupling the first reactorin heat receiving relation relative to an electrical generation facility40, and wherein the electrical generation facility, during operation,produces a source of electricity 60, and heat as a byproduct, andwherein the first chemical reactor 21 is heated to a first temperature.The method further includes steps of coupling the second chemicalreactor 22 with the source of electricity 60, and wherein the source ofelectricity generates a thermal plasma within the second chemicalreactor; and supplying a source of a first material 11 to each of thefirst and second chemical reactors 21 and 22, and wherein the first andsecond temperatures facilitate the chemical conversion of the firstmaterial 11 into the second material in the first and second chemicalreactors. As should be understood, the first material, as noted above,comprises borate and the second material comprises borohydride. Stillfurther, in the methodology as described, the step of supplying a firstmaterial may comprise providing a source of borate 11; providing asource of hydrogen 12; and providing a source of a reactive metal and/orcarbonaceous material 14-18, respectively, to form the first materialmixture. Still further, in the methodology, as described, the first andsecond temperatures, as noted above, are effective to reduce the oxygenfrom the source of borate, and the substantially simultaneoushydrogenate the source of borate 11 to convert the source of borate intothe second material which comprises a borohydride. In the methodology asdescribed, the reactive metals 16, 17 and/or 18 are selected from thegroup of metals which comprise aluminum, magnesium, titanium, chromium,silicon, tantalum, vanadium and zirconium. Additionally, the firsttemperature, as described above, is less than about 1000 degrees C., andthe second temperature is greater than about 1000 degrees C.Additionally, the electrical generation facility may be powered byfossil and/or nuclear fuels.

In the methodology for producing a borohydride as contemplated by thepresent invention, the method also includes the steps of, providing asource of a hydrated borate 11; providing a source of a reactive metal16, 17 and/or 18; mixing the source of hydrated borate with the sourceof the reactive metal(s) to form a mixture; providing a chemical reactor21, and supplying the mixture to the chemical reactor 21; sealing thechemical reactor following the step of supplying the mixture to thechemical reactor; evacuating the chemical reactor to create a negativepressure within the chemical reactor; and heating the mixture in thechemical reactor to a temperature which facilitates the conversion ofthe hydrated borate to a borohydride and the production of hydrogen gas.Still further, the present methodology as contemplated above, includesthe step of providing a source of a reactive metal 16, 17 and/or 18 andwhich extracts the oxygen from the hydrated borate to form a stableoxide of the reactive metal. Still further, the methodology ascontemplated above, includes the step of heating the mixture to atemperature of less than about 1000 degrees C. Still further, in thepractice of the method, noted above, it should be understood that thehydrogen produced by the chemical conversion of the hydrated borate 11to the borohydride increases the gas pressure within the previouslysealed chemical reactor 21.

In another aspect of the present methodology, the method for producing aborohydride further includes the steps of providing a source ofanhydrous borate 11; providing a source of a reactive metal 16, 17 or18; mixing the source of the anhydrous borate with the source of thereactive metal to form a mixture; providing a chemical reactor 21;continuously supplying the mixture to the chemical reactor 21; supplyinga source of hydrogen gas to the chemical reactor 21 while the mixture isreceived therein; and heating the mixture and the hydrogen gas which arein the chemical reactor to a temperature which facilitates theconversion of the anhydrous borate to a borohydride. In the methodologyas described above, the step of heating the mixture occurs at atemperature of less than about 1000 degrees C., and the reactive metalsare selected from the group which comprise aluminum, magnesium,titanium, chromium, silicon, tantalum, vanadium, and zirconium. Stillfurther, the anhydrous borate 11 as provided comprises sodiummetaborate. In the methodology as described above, the chemical reactormay comprise, in the alternative, a continuous flow reactor and/or achemical batch reactor.

Therefore it will be seen that the methodology of the present inventionprovides many advantages over the prior art practices which have beenconfined largely to the use of complex solvent based chemical processingsystems, and further, employs the heat and energy produced from aelectrical generation facility in order to economically produce aborohydride compound that may be effectively utilized to store hydrogenwhich may be consumed by fuel cells, and for various overland vehicleapplications.

In compliance with the statute, the invention has been described inlanguage more or less specific as to structural and methodical features.It is to be understood, however, that the invention is not limited tothe specific features shown and described, since the means hereindisclosed comprise preferred forms of putting the invention into effect.The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

1. A method for producing a borohydride, comprising: providing a sourceof borate; providing a source of hydrogen; providing a material whichchemically reduces the source of the borate to produce a borohydride anda stable oxide, wherein the material comprises a reactive metal with anoxidation state of zero and/or a carbonaceous material and wherein thereactive metal is selected from the group which consists of magnesium,silicon, aluminum, titanium, chromium, tantalum, vanadium, andzirconium; and reacting, at substantially atmospheric pressure, thesources of borate and of hydrogen and the material by supplying heat ata temperature of greater than about 1000 K which substantially effectsthe production of the borohydride.
 2. A method as claimed in claim 1,and wherein the reacting occurs in a single step.
 3. A method as claimedin claim 1, and wherein the source of hydrogen comprises water and/or ahydrocarbon and, optionally, further includes hydrogen gas.
 4. A methodas claimed in claim 1, and wherein the step of reacting the sources ofborate and of hydrogen and the material further comprises a solid statecombustion reaction of the reactive metal and/or carbonaceous material.5. A method as claimed in claim 1, and wherein the step of reacting thesources of borate and of hydrogen and the material further comprises asolid state reaction, substantially without combustion, of the reactivemetal.
 6. A method as claimed in claim 1, and wherein the step ofproviding the material further comprises: providing a mixture of thereactive metals; and wherein the step of reacting the sources of borateand of hydrogen and the mixture of reactive metals further comprises asolid state combustion of some of the reactive metals, and a solid statereaction, substantially without combustion, for the remaining reactivemetals.
 7. A method as claimed in claim 1, and wherein the step ofproviding a material further comprises providing a mixture of thereactive metals or carbonaceous material.
 8. A method as claimed inclaim 1, and wherein before the step of reacting the sources of borateand of hydrogen and the material by supplying heat at a temperature, themethod further comprises: generating heat at a temperature from theoperation of an electrical generation facility and which is employed toeffect, at least in part, the reaction of the sources of borate and ofhydrogen and the material; and generating electricity from the operationof the electrical generation facility.
 9. A method as claimed in claim8, and wherein the electrical generation facility is powered by acombustible fuel.
 10. A method as claimed in claim 8, and wherein theelectrical generation facility is powered by a nuclear reaction whichoccurs in a gas cooled nuclear reactor.
 11. A method as claimed in claim8, and wherein before the step of generating heat at a temperature froman electrical generation facility, the method further comprises:providing a first reactor and supplying the sources of borate and ofhydrogen and the material to the first reactor; providing a coolingfluid for removing heat energy which is generated by the operation ofthe electrical generation facility, and wherein the cooling fluid isheated to a temperature; and supplying the previously heated coolingfluid to the first reactor where the heated cooling fluid releases theheat energy, at least in part, to effect the reaction of the sources ofborate and of hydrogen, and the material.
 12. A method as claimed inclaim 11, and further comprising: providing a second reactor, andsupplying, at least in part, the sources of borate and of hydrogen andthe material to the second reactor; and supplying the electricitygenerated by the electrical generation facility to the second reactor togenerate a plasma which heats the sources of borate and of hydrogen andthe material to a temperature which effects the production of theborohydride.
 13. The method as claimed in claim 12, and furthercomprising: supplying the electricity which is generated by theoperation of the electrical generation facility, at least in part, toheat the first reactor to effect the reaction of the sources of borateand of hydrogen and the material to produce the borohydride.
 14. Amethod for producing a borohydride, comprising: providing a source ofborate; providing a source of hydrogen; providing a source of a reactivemetal with an oxidation state of zero and/or carbonaceous material;mixing the sources of borate, hydrogen and the reactive metal and/orcarbonaceous material; and reacting, at substantially atmosphericpressure, the mixture of the sources of borate, hydrogen, and thereactive metal and/or carbonaceous material by heating the mixture to atemperature of greater than about 1000 K which is effective to reducethe oxygen from the borate and substantially simultaneously hydrogenatethe source of borate, which has been previously reduced, to produce aborohydride.
 15. A method as claimed in claim 14, and wherein the stepof reacting the mixture of borate, hydrogen and the reactive metaland/or carbonaceous material by heating the mixture to the temperatureresults in the combustion of the reactive metal and/or carbonaceousmaterial.
 16. A method as claimed in claim 14, and wherein the step ofreacting the mixture of the borate, hydrogen and the reactive metaland/or carbonaceous material by heating the mixture to the temperatureoccurs substantially without the combustion of the reactive metal and/orcarbonaceous material.
 17. A method as claimed in claim 14, and whereinthe step of providing a source of reactive metal and/or carbonaceousmaterial further comprises: providing a mixture of reactive metalsand/or carbonaceous materials.
 18. A method as claimed in claim 14, andwherein the step of reacting the mixture of the sources of borate,hydrogen, and the reactive metal and/or carbonaceous material by heatingis facilitated by a high temperature plasma.
 19. A method as claimed inclaim 14, and wherein the step of reacting the mixture of the sources ofborate, hydrogen and the reactive metal and/or carbonaceous material byheating is facilitated without the use of a high temperature plasma. 20.A method as claimed in claim 14, and wherein the step of reacting themixture of the sources of borate, hydrogen and the reactive metal and/orcarbonaceous material by heating is achieved, at least in part, by theuse of a high temperature plasma.
 21. A method as claimed in claim 14,and further comprising: providing a first reactor; providing a secondreactor; and supplying, at least in part, the mixture which includes thesources of borate, hydrogen and reactive metal and/or carbonaceousmaterial to each of the first and second reactors, and wherein the stepof heating the mixture to the temperature which is effective to reducethe oxygen from the borate and the substantial simultaneoushydrogenation of the source of borate to produce the borohydride occursin the first and second reactors.
 22. A method as claimed in claim 21,and wherein the method further comprises: coupling the first reactor inheat receiving relation relative to an electrical generation facility,and wherein the electrical generation facility, during operation,generates heat as a byproduct, and further generates a source ofelectricity; and coupling the source of electricity to the secondreactor to facilitate the formation of a high temperature plasma.
 23. Amethod as claimed in claim 22, and wherein the method further comprises:coupling the source of electricity to the first reactor to increase thetemperature of the reactor.
 24. A method as claimed in claim 22, andwherein the first reactor is exposed to a temperature of less than about1000 degrees C., and the second reactor is exposed to a temperature ofgreater than about 1000 degrees C.
 25. A method for producing aborohydride, comprising: providing a source of borate; providing asource of hydrogen for hydrogenerating the source of borate; providing amaterial which chemically reduces the source of the borate to produce aborohydride and a stable oxide, wherein the material comprises areactive metal with an oxidation state of zero or a mixture of reactivemetals with oxidation states of zero and wherein the reactive metal(s)are selected from the group which consists of aluminum, titanium,chromium, tantalum, vanadium and zirconium; and reacting the sources ofborate and of hydrogen and the material by supplying heat at atemperature which substantially effects the production of theborohydride.
 26. A method as claimed in claim 25, and furthercomprising: reacting a source of a carbonaceous material with thereactive metal or mixture of reactive metals.
 27. A method as claimed inclaim 25, and wherein the step of reacting the reactive metal, ormixture of reactive metals with the sources of borate and hydrogenfurther comprises: conducting a solid state reaction with or withoutcombustion of some or all of the reactive metals or mixture of reactivemetals.
 28. A method as claimed in claim 1, and wherein the heat issupplied at a temperature of greater than about 1150 K.
 29. A method asclaimed in claim 1, and wherein the heat is supplied at a temperature ofgreater than about 1000° C.